Apparatus for burning pulverized fuel



July 30, 1935. J. B. TOWNSEND APPA RATUQFOR BURNING PULVERIZED FUEL Filed Aug. 12, 1931 2 Sheets-Sheet l 1 IIIP N IIPI i Ir I N VEN TOR. Jo/m 5. Emma 71d BY Mk1 v A TTORNEY.

July 30, 1935. J, TOWNSEND 7 2,009,641

Filed Aug. 12, 1931 2 Sheets-Sheet 2 TOR send

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Patented July 30, 1935 UNITED STATES APPARATUS FOR BURNING PULVERIZED FUEL John B. Townsend, Newark, Ohio, assignor to A. H. Heisey (L Company, Newark, Ohio Application August 12, 1931, Serial N0. 556,618

3 Claims. (01. 11o 2s).

.Among these defects has been the difiiculty of obtaining complete combustion of. the fuel being complete combustion of the fuel by a simple and comparatively inexpensive apparatus.

Other objects will appear as thisdescription progresses.

In its preferred form, my invention contemplates the provision of a furnace with a central upstanding cylindrical portion disposed within the furnace and having its outer periphery spaced.

from the inner periphery of the furnace. The annular space thus formed is utilized as a combustion chamber and I preferably inject pulverized fuel into this chamber with a constant draft of air which causes the particles of the fuel to circulate and remain suspended until complete combustion occurs. preferably contemplates the introduction of additional air through ducts in the central cylindrical portionof the furnace and thence into the annular combustion chamber so that it reaches this combustion chamber in a preheated'state and further enhances the combustion action.

The apparatus which I preferably use is shown in the accompanying drawings wherein similar characters designate corresponding parts and wherein:

a Figure l is a perspective view of my furnace with parts broken away to illustrate the interior thereof.

Figure 2 is a side elevation of the structure shown in Figure 1.

Figure 3 is a section taken on line 3--3 of Figure 2 Figure 4 is a section taken on line 4-4 of Figure 5 is a section taken on line 5-5 of Figure 2. r t i 1 Figure 6 is a vertical section of a slightly modified type of furnace, made in accordance with my invention.

7 In the drawings, my furnace structure is shown as comprising an exterior portion I which may Furthermore, my invention be of rectangular cross-section or of other suitable form' and which is provided with an interior cavity that is preferably of cylindrical form. Dis- PATENT oFFicE 2 posed within this cavity is an upstanding inner 7 member 2 which is of cylindrical formthroughout the greater portion of its length, but which has an upper portion 3 of frusto-conical form. This inner member 2 and the. upper portion 3 thereof are of such diameter and so located within the cavity of the member I that they form an annular combustion chamber 4, which extends from top tobottom of the furnace. I

At its upper end, the annular combustion chamber communicates with a passage 5, preferably of cylindrical form, extending into and through an annular flange 6 integrally formed on the top'of the outer member I. Passage 5 communicates with a box i, from the upper end of vhich lead a plurality of fiues 8 that may be connected with a stack or other form of draft-producing means. The box I and the fines 8 form a part of a boiler 9 which may contain water to be heated by the products of combustion passing through this box I and these flues. Powdered fuel is preferably introduced into the combustion chamber of the furnace through one side wall thereof and preferably adjacent one of the corners 'of the furnace structure. As shown in Figure 1, I, may utilize a. crushing apparatus ID from which the powdered'fuel is drawn by -means of a ien H connected to the coal-crushing apparatus by a pipe I Z. Leading from the fan I! is a pipe l3 which terminates in a nozzle l4 that projects through a plate l5 and intoa port l6 in the furnace wall.

ber 2 and the upper portion 3 thereof and the draft applied to fines 8 assists in maintaining suspension of this fuel.

Adjacent the delivery end of nozzle I4 I preferably provide a plurality of openings l'l, best illustrated in Figure 4, and provide means (not shown) for forcing air through these openings which'is delivered-to the coal at right angles to the path of travel of this coal. Additional air ducts are disposed in the central member 2 and these air ducts take the form of a vertical duct l8, designed to be fed with air under pressure by .erably disposed centrally of the member 2 and extends approximately one-half the height thereof where it communicates with cross-ducts 20 that lead into the combustion chamber 4.

It will be seen from this that the fuel-laden air delivered into the combustion chamber 4 is fur- .means of a pipe 19. The vertical duct 18 is pref through the medium of an inlet duct 28.

The furnace structure is further preferably provided with a suitable number of clean-out ports, preferably one at each corner of the furnace. These ports are illustrated best in Figure 1 where they are designated 22 and shown provided with doors 22a.

In operation, it will be apparent that the powdered fue enters the annular combustion chamber and whirls about the central member 2 and portion 3 thereof. The coal thus introduced may be lighted by means of a wick that may be introduced through opening 23 which is located ad jacent the nozzle which delivers the powdered fuel.

The powdered fuel which is thus delivered to the combustion chamber will be entirely maintained in suspension until combustion is completed or, if any larger lumps of coal should drop to the bottom of the combustion chamber, they will be ignited by the flames within this chamber and completely consumed. Obviously, the additional air introduced under pressure, both the air introduced through the ports 1 and a" introduced through the ports 29, will serve to further maintain suspension and complete combustion.

In the modified form of apparatus shown in Figure 6, my invention is shown as applied to a hot-airfurnace. The fuel burning apparatus is substantially identical with the apparatus just described, except that the heated products of combustion pass intothe interior 24 of a domelike structure 25 and are delivered therefrom by means of a flue 2B. The air to be heated by the products of combustion enters a chamber29, of which the dome-like member25 forms a wall It entersthe chamber 29 which surrounds the dome 25 and then passes to any selected points by means of ducts such as shown at 39 and 3|. I

It will be seen from this description that I have provided a simple structure of furnace for burning powdered fuel and that the method of introducing this powdered fuel and subjecting it to air and drafts insures that complete combustion will be procured while the particles of fuel are suspended. Furthermore, the structure of the furnace is such that it may be readily cleaned and is also obvious that this furnace may be cheaply constructed;

It will be understood that by the term powdered fuel which is used in this specification and the claims appended hereto, I intend to cover any fuel which consists of fine particles that may be carried in suspension bya current of air or gas.

Having thus described my invention, what I claim is:

' l. A furnace for burning powdered fuel comprising an outer member with a cylindrical cavity formed therein and extending the greater portion of the height thereof, a frustro-conical cavity formed in the upper portion of said outer member and communicating with the upper end of said cylindrical cavity, an inner'member of substantially cylindrical shape disposed in said cylindrical cavity and spaced from the outer walls thereof to form an annular combustion chamber extending approximately the entire height thereof, said cylindrical member having a frustro-conical portion on its upper end disposed within the frustro-conical cavity in the upper portion of said outer member and being spaced from the walls of said cavity to produce an annular combustion chamber in the upper portion of said outer member wlr'ch communicates with said first-named annular combustion chamber and which gradually decreases in diameter towards its upper end, a chamber at the upper end of said furnace with which the upper end of said last-named chamber communicates, and means for injecting powdered fuel into said furnace.

g 2. A furnace for burning powdered fuel comprising an outer member with a cylindrical cavity formed therein and extending the greater portion of the height thereof, a frustro-conical cavity formed in the upper portion of said outer member and communicating with the upper end of said cylindrical cavity, an inner member of substantially cylindrical shape disposed in said cylindrical cavity and spaced from the outer walls thereof to form an annular combustion chamber extending approximately the entire height thereof, said cylindrical member having a frustro-conical portion on its upper end disposed within the frustroconical cavity in the upper portion of said outer member and being spaced from the walls of said cavity to produce an annular combustion chamber in the upper portion of said outer member which communicates with said first-named annular combustion chamber and which gradually decreases in diameter towards its upper end, a chamber at the upper end of the furnace with which the upper end of said last-named chamber communicates, a passageway through which fuel with air under pressure is forced into said annular combustion chamber, and means for applying draft of air to the fuel-laden air and at an angle to the path of travel of the fuel-laden air during its passage into said chamber.

3. A furnace for burning powdered fuel comprising an outer member with a cylindrical cavity formed therein and extending the greater portion of the height thereof, a frustro-conical cavity formed in the upper portion of said outer member andcommunicating with the upper end of said cylindrical cavity, an inner member of substantially cylindrical'shape disposed in said cylindrical cavity and'spaced from the outer walls thereof to form an annular combustion chamber extending approximately the entire height thereof, said cylindrical member having a frustro-conical portion on its upper end disposed within the frustro-conical cavity in the upper portion of said outer member and being spaced from the walls of said cavity to produce an annular combustion chamber inthe upper portion of said outer member which communicates with said first-named annular combustion chamber and which gradually decreases in diameter towards its upper end, a chamber at the upper end of the furnace with which the upper end of said last-named chamber communicates, means for injecting powdered fuel into said furnace, and means for introducing preheated air into said combustion chamber.

- JOHN B. TOWNSEND. 

